Highly fluorinated, chloro-substituted organic compound-containing emulsions and methods of making and using them

ABSTRACT

This invention relates to compositions comprising highly fluorinated, chloro-substituted, non-cyclic organic compounds having 7 to 9 carbon atoms and to processes of making and using them. More particularly, this invention relates to emulsions comprising those highly fluorinated, chloro-substituted organic compounds. This invention also related to emulsion comprising noncyclic perfluorochlorethers having 7 to 10 carbon atoms, preferably 7 to 9 carbon atoms. These novel emulsions have various medical and oxygen transport applications. They are especially useful medically as contrast media, for various biological imaging modalities such as nuclear magnetic resonance, ultrasound, x-ray, computed tomography,  19  F-magnetic resonance imaging, and position emission tomography, as oxygen transport agents or &#34;artificial bloods,&#34; in the treatment of heart attack, stroke, and other vascular obstructions, as adjuvants to coronary angioplasty and in cancer radiation treatment and chemotherapy.

This application is a 371 of PCT/US92/10736, filed Dec. 11, 1992, whichis a continuation-in-part of U.S. application Ser. No. 07/806,692, filedDec. 12, 1991, now U.S. Pat. No. 5,403,575.

TECHNICAL FIELD OF INVENTION

This invention relates to compositions comprising highly fluorinated,chloro-substituted, non-cyclic organic compounds having 7 to 9 carbonatoms and to processes of making and using them. More particularly, thisinvention relates to emulsions comprising those highly fluorinated,chloro-substituted organic compounds. This invention also relates toemulsions comprising non-cyclic perfluorochloroethers having 7 to 10carbon atoms, preferably 7 to 9 carbon atoms. These novel emulsions havevarious medical and oxygen transport applications. They are especiallyuseful medically as contrast media for various biological imagingmodalities, such as nuclear magnetic resonance, ¹⁹ F-magnetic resonanceimaging, ultrasound, x-ray, computed tomography and position emissiontomography, as oxygen transport agents or "artificial bloods," in thetreatment of heart attack, stroke, and other vascular obstructions, asadjuvants to coronary angioplasty and in cancer radiation treatment andchemotherapy.

BACKGROUND OF THE INVENTION

Highly fluorinated organic compounds, and particularly perfluorocarboncompounds, are well known to be both stable and chemically inert. Duringthe past 20 years much attention has focused on the use of suchcompounds in biological systems because they are capable of dissolvingand transporting large amounts of oxygen. These properties make thempotentially useful as contrast media, oxygen transport agents or"artificial bloods", in the treatment of heart attack, stroke, and othervascular obstructions, as adjuvants to coronary angioplasty, and incancer radiation treatment and chemotherapy.

Among the highly fluorinated organic compounds that are said to beuseful in such applications are perfluorocarbon compounds, e.g.,perfluorodecalin, perfluoroindane, perfluorotrimethyl bicyclo 3.3.1!nonane, perfluoromethyl adamantane, perfluorodimethyl adamantane, andperfluoro-2,2,4,4-tetramethylpentane; 9-12C perfluoro amines, e.g.,perfluorotripropyl amine, perfluorotributyl amine,perfluoro-1-azatricyclic amines; bromofluorocarbon compounds, e.g.,perfluorooctyl bromide and perfluorooctyl dibromide; F-4-methyloctahydroquinolidizine and perfluoro ethers, including chlorinatedpolyfluorocyclic ethers. Such compounds are described, for example, inU.S. Pat. Nos. 3,962,439, 3,493,581, 4,110,474, 4,186,253, 4,187,252,4,252,827, 4,423,077, 4,443,480, 4,534,978, 4,686,024, 4,865,836,4,866,096 and 4,868,318, European patent applications 80716 and 158,996,British patent specification 1,549,038 and German Offen. 2,650,586.

For intravenous use, highly fluorinated organic compounds must bedispersed as emulsions. See, 35 e.g., L. C. Clark, Jr. et al.,"Emulsions Of Perfluorinated Solvents For Intravascular Gas Transport,"Fed. Proc., 34(6), pp. 1468-77 (1975); K. Yokoyama et al., "APerfluorochemical Emulsion As An Oxygen Carrier," Artif. Organs (Cleve),8(1), pp. 34-40 (1984); and U.S. Pat. Nos. 4,110,474 and 4,187,252.Neat, highly fluorinated organic compounds are immiscible in blood.

Such emulsions must not only contain a high enough concentration of thehighly fluorinated organic compound to be effective in the desired levelof oxygen transport, they must also by capable of sterilization,preferably by heat, have long term stability in the fluid or non-frozenstate, persist for sufficiently long times in the blood stream todeliver useful quantities of oxygen and yet be eliminated rapidly enoughfrom the body to avoid toxicity and retention in body parts and organs.

SUMMARY OF THE INVENTION

This invention relates to novel compositions comprising highlyfluorinated, chloro-substituted, non-cyclic organic compounds having 7to 9 carbon atoms and to processes of making and using them. Moreparticularly, this invention relates to novel highly fluorinated,chloro-substituted organic compound-containing emulsions.

The emulsions of this invention are useful in various oxygen transportapplications. They are particularly useful in medical applications,e.g., as contrast media for various biological imaging modalities,including nuclear magnetic resonance, ultrasound, ¹⁹ F-magneticresonance imaging, x-ray, computed tomography, and position emissiontomography, as oxygen transport agents or "artificial bloods", in thetreatment of heart attack, stroke, and other vascular obstructions, asadjuvants to coronary angioplasty a cancer radiation and chemotherapy.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts the percent dose of PFBCBE remaining in tissue at 2, 16,30 and 60 days post-infusion.

DETAILED DESCRIPTION OF THE INVENTION

In order that the invention herein described may be more fullyunderstood, the following detailed description is set forth.

The present invention relates to various highly fluorinated,chloro-substituted organic compounds ("chlorofluorochemicals"). Thesecompounds, particularly, emulsions containing them, are useful invarious medical and oxygen transport applications. The highlyfluorinated, chloro-substituted, organic compounds of this inventioncontain 7 to 9 carbon atoms, are non-cyclic, and include, for example,highly fluorinated chlorochemicals, particularly,chloroperfluorochemicals, including perfluorochloroethers, and highlyfluorinated bromochlorochemicals, particularly,bromochloroperfluorochemicals. We prefer perfluorochlorochemicals.

The compounds of this invention typically, contain one to three chloroor bromo substituents in total, at least one being chloro. Preferably,only chloro substituents are present. More preferably, the compounds ofthis invention have two chloro substituents.

Although the chloro and bromo substituents can in principle be locatedon any carbon in the compound, we prefer that when there is more thanone such substituent, that they be on different carbons (i.e., notgeminal). In the most preferred chlorofluorochemical of thisinvention--1,8 perfluorodichlorooctane--the chloro substituents arelocated at opposite ends of the carbon chain. One route of synthesis ofthis compound is described in A. Y. Zapevalov et al., "Synthesis AndReactions Of Oxygen-Containing Organofluorine Compounds VI.Polyfluorinated Ketones With A Trifluoromethyl Group", Journal ofOrganic Chemistry of the USSR, 14, pp. 239-242 (July 1978).

This invention also contemplates N-, O-, and S-containing highlyfluorinated, chloro-substituted, non-cyclic organic-compounds having 7to 9 carbon atoms. For example, tertiary amines, ethers or sulfones maybe employed. It should be understood that any of the highly fluorinated,chloro-substituted organic compounds of this invention may be mixedtogether or with other well known highly fluorinated organic compoundsand used in the emulsions of this invention.

The highly fluorinated, chloro-substituted organic compounds of thisinvention are non-cyclic, straight or branched chain compounds having 7to 9 carbon atoms, preferably saturated aliphatic compounds. Compoundshaving 8 carbon atoms are preferred. Dichloro-substituted organiccompounds having 8 carbon atoms, e.g., perfluorodichlorooctane andperfluoro-bis-chlorobutyl ether, are more preferred. The most preferredcompound in accordance with this invention is1,8-perfluorodichlorooctane ("PFDCO").

In addition, this invention also contemplates perfluorochloroethershaving 7 to 10 carbons, and more preferably perfluorochloroethers having7 to 9 carbon atoms. The perfluorochloroethers contemplated within thescope of this invention include: Cl-(CF₂)₄ -O-!₂ CF₂, Cl-(CF₂)₃ -O-!₂CFCF₃, Cl-C₂ F₄ -O-C₂ F₄ -O-!₂ CF₂, C₄ F₉ -O-)₂ CFCF₂ -Cl, C₅ F₁₁-O-CF(CF₂ -Cl)₂, (Cl-CF₂)₂ CF-O-!₂ CF₂, C₄ F₉ -O-C(CF₂ -Cl)₃, Cl-CF₂C(CF₃)₂ CF₂ -O-(CF₂)₄ -Cl, Cl-C₂ F₄ -O-CF(CF₃)CF(CF₃)-O-C₂ F₄ -Cl, C₈F₁₇ -O-CF₂ -Cl, C₅ F₁₁ -O-(CF₂)₅ -Cl, CF₃ -O-(CF₂)₈ -Cl, Cl-C₂ F₄-O-(CF₂)₄ -O-C₂ F₄ -Cl, Cl-(CF₂ CF₂ -O-)₃ C₂ F₄ -Cl, (CF₃)₃ C-O-(CF₂)₅-Cl, C₄ F₉ -O-CF₂ CF(CF₂ -Cl)-O-CF₃, C_(4F) 9-O-C₂ F₄ -O-C₂ F₄ -Cl , C₆F₁₃ -O-C₂ F₄ -O-C₂ F₄ -Cl, and perfluoro-bis-chlorobutyl ether. Weprefer C₄ F₉ -O-C₂ F₄ -O-C₂ F₄ -C1, C₆ F₁₃ -O-C₂ F₄ -O-C₂ F₄ -Cl andperfluoro-bis-chlorobutyl ether, most preferablyperfluoro-bis-chlorobutylether.

Several methods exist for fluorination of chloroether orfluorochloroether precursors to produce the perfluorochloroethers thatare useful in this invention. Such precursors, e.g.,bis-chlorobutylether, butoxyethoxyethylchloride andhexyloxyethoxyethylchloride, are commercially available or can bereadily synthesized by one of ordinary skill in the art.

We prefer either solid phase or liquid phase direct fluorination asdescribed in U.S. Pat. Nos. 4,755,567, 4,859,747, 5,093,432, and inpublished PCT application WO 90/06296. The direct fluorination of thechloroether or fluorochloroether precursors can be carried out atmoderate or near ambient temperatures, e.g., -20° C. to +50° C., using astoichiometric excess of fluorine gas. Preferably the fluorine gas isdiluted with an inert gas, such as nitrogen, to minimize or avoid thehazards of pure fluorine gas and to control the amount of heat generatedupon initial contact of the precursor with fluorine. The fluorinationcan be carried out in an oxygen- and water-free environment and can becarried out in the presence of a solid particulate scavenger, e.g.,sodium fluoride, for the hydrogen fluoride by-product that is generated.

We prefer to use liquid phase direct fluorination in the absence of ahydrogen fluoride scavenger. The fluorochloroether precursor isdispersed in an inert liquid, such as a fluorocarbon orfluorochlorocarbon liquid. The reaction is conducted at a temperatureand inert gas flow rate sufficient to volatilize the hydrogen fluorideby-product and enable its removal from the fluorination zone as it isgenerated. See, e.g., published PCT application WO 90/06296.

For intravenous use, the highly fluorinated, chloro-substituted organiccompounds of this invention are dispersed as emulsions. Such emulsionsmay comprise up to about 60% (by volume) of the chloro-containingcompound. Preferably, the emulsions of this invention comprise fromabout 10% to about 50% (by volume) of the highly fluorinated,chloro-substituted organic compound. Most preferably, emulsionscontaining about 25% to about 40% (by volume) of a chlorofluorochemicalof this invention are used.

The emulsions of this invention are made using conventional means andmethods and include components common to the well known emulsions ofhighly fluorinated organic compounds. Among the surfactants useful inthe emulsions of this invention are any of the known anionic, cationic,nonionic and zwitterionic surfactants. Preferred are the nonionicsurfactants, such as alkyl or aryl compounds, whose hydrophilic partconsists of polyoxyethylene chains, sugar molecules, polyalcoholderivatives or other hydrophilic groups, for example, any of the BASFWyandotte formulations of polyoxyethylene and polyoxypropylene oxidessold under the tradename "Pluronic", for example, Pluronic F-68 orF-108, or zwitterionic surfactants. Fluorinated surfactants, e.g.,ATSURFS® F-31 (ICI, Wilmington, Del.), may also be used in the emulsionsof this invention. See, e.g., Riess et al., "Design, Synthesis andEvaluation of Fluorocarbons and Surfactants for In Vivo Applications,New Perfluoroalkylated Polyhydroxylated Surfactants", Artif. CellsArtif. Organs, 16, pp. 421-30 (1988). Again, combinations of thesesurfactants may, of course, be used in the emulsions of this invention.In addition, mixtures of compounds, one or more of which are notsurfactants, but which compounds when combined act as surfactants mayalso be usefully employed as the surfactant component of the emulsionsof this invention.

Preferably, the surfactants used in the emulsions of this invention arephysiologically acceptable, for example, one or more of the following:egg and soybean phosphatides, lecithin, and alkyl salts of oleic acid,such as sodium oleate. More preferable is lecithin. While the amount ofa particular surfactant used in the emulsions of this invention dependson the amounts and properties of the other components of the emulsion,typically we employ between about 0.5 and 10% (by weight of the totalemulsion) of surfactant. More preferably, we use about 1 to about 4% (byweight).

The emulsions of this invention may also contain an oil that is notsubstantially surface active and not significantly water soluble. Suchoils are, for example, described in EP 231,091, WO 89/10118 and U.S.Pat. No. 4,866,096. They include liquid fatty oils, hydrocarbons, waxes,such as monoesters of a fatty acid and a monohydroxide alcohol, longchain ethers, diglycerides, triglycerides, silicone oils and nitriles.Among the useful oils in these classes are palmitoyl oleate, octylnitrile, dodecyl nitrile, soy(bean) oil, safflower oil, mineral oil,hexadecane, and diglycerides and triglycerides having a C₁₂₋₁₈ carbonchain. Of course, any mixture of triglycerides and or oils that aresimilar in fatty acid composition to triglycerides may be used. Theseoils may be used singly or in various combinations in the emulsions andprocesses of this invention. When our emulsions are to be usedmedically, the oil or combination of oils must, of course, bephysiologically acceptable. In that regard, we prefer physiologicallyacceptable liquid fatty oils, such as soybean and safflower oils.

The amount of oil, or oils, if present, in the emulsions of thisinvention may vary over a wide range of concentrations depending on theconcentration and properties of the other components of the emulsion,being principally dependent on the characteristics of the highlyfluorinated, chloro-substituted organic compound component of theemulsion. The actual oil concentration to produce an acceptable emulsionfor any given set of components is easily determined as taught by thisinvention using the simple techniques of preparing the emulsions atvarious oil concentrations. Within this teaching, we typically employbetween about 0.5 and 20 w/v% of oil or a mixture of oils. Preferably,we employ between about 1 and 5 w/v%.

In addition to the highly fluorinated, chloro-substituted organiccompounds, oils, surfactants and water, the emulsions of this inventionmay also contain other components conventionally used in "artificialbloods" or blood substitutes, oxygen transport agents or contrast media.For example, emulsions according to this invention usually also containan isotonic agent, typically sugars, such as glucose, mannose andfructose, glycerin, or other polyhydric alcohols to adjust the osmoticpressure of the emulsion to about that of blood. Osmolarity may also beadjusted after sterilization by buffers such as sodium chloride, sodiumbicarbonate, magnesium chloride, and the like, to reduce the possibilityof red blood cell injury. For example, we typically use between about 1and 2.5% (by weight of the emulsion) of such agents. However, otheramounts and other osmotic pressure controlling agents, e.g., Tyrodesolution, could as well be used. In addition, these emulsions may bemixed with 0.9% saline, lactated Ringer's solution, and serum and serumproducts with no adverse effect on emulsion particle size and stability.The emulsions of this invention may also include other components, suchas osmotic agents, e.g., dextran or hydroxyethyl-starch (HES), andantioxidants.

In the most preferred emulsions of this invention, thechlorofluorochemical is PFDCO, the surfactant is egg yolk lecithin, andthe oil, if present, is safflower oil. Glycerin is typically added tothe emulsion to adjust isbtonicity. In the most preferred emulsions ofthis invention, the PFDCO is present in about 40% by volume, thelecithin in about 2.0 w/v%, and the safflower oil, if present, in about2.0 w/v% of the emulsion.

As described above, the highly fluorinated, chloro-substituted organiccompound-containing emulsions of this invention are useful as contrastmedia. Lacking hydrogen, they produce a signal void in the selected bodypart which can be distinguished from adjacent body parts by variousbiological imaging modalities, e.g., nuclear magnetic resonance,ultrasound, x-ray, computed tomography and position emission tomography.In addition, the compounds of this invention and their emulsions areuseful as contrast agents and for direct imaging in ¹⁹ F-MRI.

When used as contrast media, the emulsions of the invention may beadministered, for example, by bolus, orally, subcutaneously,intraperitoneally, intrathecally, or other medically approved method ofadministration, e.g., catheterization, to the degree necessary such thatthe emulsions are capable of producing clear concise shadows of thedesired part or parts of the anatomy.

The emulsions of this invention may also be used as artificial bloodsand infused intravenously to animals or humans suffering from blood lossor oxygen depleted blood. Accordingly, the emulsions of this inventionmay also be used to sustain the oxygen requirements of living organismsor their cellular constituents, e.g., cell lines. Besides the utility ofsuch artificial bloods for animals and humans, these emulsions can beused as a perfusate for the preservation of internal organs, such aswith organ transplants, for extended periods outside the body.

Publications demonstrating the usefulness of highly fluorinated organiccompound-containing emulsions to preserve organs outside the body of ahuman or an animal include Kawamura et al., "A New Simple Two layer(Euro-Collins' Solution/Perfluorochemical) Cold Storage Method ForPancreas Preservation", Transplantation Proc., 21, pp. 1376-77 (1989);Segel and Ensunsa, "Albumin Improves Stability And Longevity OfPerfluorochemical-Perfused Hearts", Am. J. Physiol., 254, pp. H1105-12(1988); Segel et al., "Prolonged Support of Working Rabbit Hearts UsingFlusol-43 Or Erythrocyte Media", Am. J. Physiol., 252, pp. H349-59(1987); Segel and Rendig, "Isolated Working Rat Heart Perfusion WithPerfluorochemical Emulsion Fluosol-43", Am. J. Physiol., 242, pp.H485-89 (1982). The chlorofluorochemicals and emulsions of thisinvention are similarly useful.

The ability of highly fluorinated organic compounds to carry oxygen makethem useful when dispersed as emulsions to enhance cancer radiationtreatment and chemotherapy, in coronary balloon angioplasty, and in thetreatment of heart attack, stroke and other vascular obstructions.Publications demonstrating the usefulness of such emulsions to enhancecancer radiation treatment and chemotherapy include Teicher and Rose,"Oxygen-Carrying Perfluorochemical Emulsion As An Adjuvant To RadiationTherapy In Mice", Cancer Res., 44, pp. 4285-88 (1984); Teicher and Rose,"Effects Of Dose And Scheduling On Growth Delay Of The Lewis LungCarcinoma Produced By The Perfluorochemical Emulsion, Fluosol-DA", Int.J. Radiation Oncology Biol. Phys.. 12, pp. 1311-13 (1986); Rockwell etal., "Reactions of Tumors And Normal Tissues In Mice To Irradiation InThe Presence And Absence Of A Perfluorochemical Emulsion", Int. J.Radiation Oncolovy Biol. Phys., 12, pp. 1315-18 (1986); Teicher andRose, "Perfluorochemical Emulsions Can Increase Tumor Radiosensitivity",Science, 223, pp. 934-36 (1984); Teicher et al., "Effect Of VariousOxygenation Conditions And Fluosol-DA On Cytotoxicity And AntitumorActivity Of Bleomycin In Mice", J. Natl. Cancer Inst., 80, pp. 599-603(1988). The chlorofluorochemicals and emulsions of this invention aresimilarly useful.

Publications demonstrating the usefulness of highly fluorinated organiccompound-containing emulsions to minimize the adverse effects ofcoronary balloon angioplasty include Virmani et al., "MyocardialProtection By Perfluorochemical Infusion During Transient IschemiaProduced By Balloon Coronary Occlusion", Am. Heart J., 116, pp. 421-31(1988); Jaffe et al., "Preservation Of Left Ventricular EjectionFraction During Percutaneous Transluminal Coronary Angioplasty By DistalTranscatheter Coronary Perfusion of Oxygenated Fluosol DA 20%", Am.Heart J., 115, pp. 1156-64 (1988); Cleman et al., "Prevention ofIschemia During Percutaneous Transluminal Coronary Angioplasty ByTranscatheter Infusion Of Oxygenated Fluosol DA 20%", Circulation, 74,pp. 555-62 (1986); Anderson et al., "Distal Coronary Artery PerfusionDuring Percutaneous Transluminal Coronary Angioplasty", Am. Heart J.,110, pp. 720-26 (1984). The chlorofluorochemicals and emulsions of thisinvention are similarly useful.

Publications demonstrating the usefulness of highly fluorinated organiccompound-containing emulsions for treating heart attack, stroke andvascular occlusions include Peerless et al., "Modification of CerebralIschemia With Fluosol", Stroke, 16, pp. 38-43 (1985); Osterholm et al.,"Severe Cerebral Ischemia Treatment By Ventriculosubarachnoid PerfusionWith An Oxygenated Fluorocarbon Emulsion", Neurosurg., 13. pp. 381-87(1983); Peerless et al., "Protective Effect of Fluosol-DA In AcuteCerebral Ischemia", Stroke, 12, pp. 558-63 (1981); Forman et al.,"Reduction Of Infarct Size With Intracoronary Perfluorochemical In ACanine Preparation of Reperfusion", Circulation, 71, pp. 1060-68 (1985).The chlorofluorochemicals and emulsions of this invention are similarlyuseful.

The emulsions of this invention may be prepared by conventional mixingof the highly fluorinated components (discontinuous phase) with anaqueous (continuous) phase and a surfactant. Alternatively, theemulsions of this invention may be prepared by mixing an aqueous phasewith any suitable surfactant, and optionally, osmotic agents, bufferingagents, electrolytes if desired, other emulsifying agents, additionalanti-oxidants, and the like into an aqueous dispersion. The highlyfluorinated components may then be mixed into the aqueous dispersion soas to provide an emulsion of this invention.

The emulsions of this invention may also be prepared by pre-mixing anaqueous dispersion with any suitable surfactant(s) and, optionally,other conventional components of artificial bloods, e.g., osmotic agentsand the like. The oil, if present, may then be mixed into theabove-described aqueous dispersion at a predetermined rate. The highlyfluorinated components may then be mixed in at a predetermined rate soas to provide an emulsion of this invention.

The resulting emulsion is sterilized, preferably at temperatures inexcess of 115° C., more preferably at about 121° C., packaged andotherwise processed for storage and use.

The mixing, pre-mixing if desirable, and emulsification of thecomponents may be done using any of the conventional mixers,homogenizers, and emulsifiers. For example, one may employ Fisher brandtouch mixers and microfluidizers or Gaulin homogenizers. In preparingthe emulsions of this invention, we prefer to use an inert atmosphere(e.g., N₂) to prevent degradation of the surfactant and fatty oils, ifpresent, and to use temperatures between about 45° C. and 55° C.

In order that this invention be more fully understood, preferredemulsions prepared and used in accordance with the description of thisinvention are provided below by way of example.

EXAMPLES

Preparation Of Emulsion (Method A)

Powdered, refined, egg yolk lecithin was obtained from Kabi Vitrum anddispersed in sterile H₂ O (Millipore®) under an inert atmosphere (N₂)using a Waring™ Blender at high speed for 2-3 minutes. The lecithin sodispersed was collected under an inert atmosphere and stored at 4° C.All lecithin dispersions so prepared were used within one week of theirpreparation.

The lecithin dispersion (18.00% by weight) was suspended by vigoroushandshaking and then a 17.01 g portion was transferred to a 250 ml inletreservoir, again under an inert atmosphere, which fed a Microfluidizer™homogenizer. The lecithin dispersion was then further diluted with 81.85g of water and 2.94 g of glycerin prior to starting the homogenizer. Thehomogenizer was then started and the pressure was maintained at about8000 psi at a flow rate of about 350 ml/min. for about 2 minutes. Oil(3.50%) was slowly introduced (1-2 minutes) in an adjacent port, belowthe level of the inlet reservoir, as close to the homogenizer inlet aspossible. The chlorofluorochemical (117.6 g, 70.0 ml) was slowly added(6-10 minutes) through the same adjacent port. The homogenate was cycledthrough the valves of homogenizer for about an additional 15 minutes.The pH was maintained at about 8.5 or higher by the controlled additionof 0.47 M Na₂ CO₃ or other base. The resulting emulsion, comprising 1.75w/v% lecithin, 2.0 v/v% oil, and 40.0 v/v% chlorofluorochemical, wasthen sterilized in a rotating steam autoclave at about 121° C. for about15 minutes.

Preparation of Emulsion (Method B)

A one quart Waring™ blender was first loaded with the appropriate chargeof sterile water (137.0 g), glycerin (4.09 g), lecithin (5.07 g),surfactant (5.02 g), and chlorofluorochemical (177.05 g, 98.91 ml) andmixed at high speed for 2-3 minutes. The entire contents were then addedto a 250 ml inlet reservoir in a Microfluidizer™ homogenizer. Thehomogenizer was started and the pressure was maintained at about 8000psi at a flow rate of about 350 ml/min. The pH was maintained at about8.00 or higher by controlled addition of 0.47 M Na₂ CO₃ or other base.The material was cycled through the homogenizer for about 15 minutes. Inthe case of larger batches (>500 ml), the emulsion was alternatelycycled between two different vessels for a total of six passes. Theresulting emulsion, comprising 1.24 w/v% glycerin, 2.01 w/v% lecithin,1.99 w/v% surfactant and 38.23 v/v% chlorofluorochemical, was thensterilized in a rotating steam autoclave at about 121° C. for about 15minutes.

Preparation of Emulsion (Method C)

Water (about 3000.0 g) was placed in a 5 liter vessel equipped with ahigh speed stirrer, nitrogen inlet, and solids addition inlet. Thestirrer was started and about 270.70 g of lecithin and about 257.7 g ofoil were added to the vessel and maintained under Nitrogen atmosphere.Blending continued at about 1800 rpm for about 15 minutes. During thistime, the ingredients formed a coarse emulsion. This coarse emulsion wastransferred to a 14 Liter vessel equipped with a low speed stirrer,nitrogen inlet, water cooling jacket and feed line. With mild agitation,about 4139.80 g of water was added, followed by a 5% solution of aqueoussodium carbonate (about 56.6 g). A Gaulin M15R homogenizer valve was setto an operational pressure of about 7500-9000 psi and the coarseemulsion was recirculated through this valve while about 9104.90 g ofchlorofluorochemical was added to the mixture, prior to the homogenizervalve, at a rate of about 15 g/min. After addition of thechlorofluorochemical was complete, the entire emulsion was cycled intoan alternate 14 Liter vessel (equipped identically to the first) withhomogenization continuing at the aforementioned valve pressure of about7500-9000 psi. The homogenate was passed through the homogenizing valvefor about ten cycles, each cycle being passed into an alternate vessel.During this time, the temperature of the homogenate was maintainedbetween about 30° C. (at the inlet side of the valve) and 53° C. (at theoutlet side of the valve) by the application of cooling water to thevessel jackets. The emulsion was collected, bottled into 350 mLcontainers, and sterilized for 15 minutes at 121° C. in an autoclaveequipped with a rotating basket.

Of the methods described above, the particular method employed in thepreparation of the following illustrative emulsions is indicated inbrackets. In Examples 1-9 and 11, the chlorofluorochemical emulsionswere prepared on a small scale in microfluidizers at a pressure ofbetween about 7,000 and 9,000 psig for 10 to 15 minutes. Example 10 wasprepared on a large scale in a Gaulin homogenizer. The components of theaqueous phase which typically comprise about 60% by volume of theseemulsions are not shown.

    ______________________________________                                        Emulsion DBF02-76 (PFCN).sup.a  A!                                            ______________________________________                                                   Post Sterilization                                                 Ingredient   w/w %       w/v %   v/v %                                        ______________________________________                                        lecithin     1.35        1.77    1.77                                         safflower oil                                                                              1.51        1.99    2.16                                         glycerin     1.23        1.61    1.28                                         PFCN         53.73       70.54   39.41                                        ______________________________________                                                     pH     Osm.sup.b Visc.sup.c                                                                         PSD.sup.d                                  ______________________________________                                        pre-sterilization                                                                          9.02   308       5.66 260                                        post-sterilization                                                                         8.24   311       7.41 267                                        ______________________________________                                         .sup.a Perfluorochlorononane.                                                 .sup.b Osmolarity (milliosmols)                                               .sup.c Viscosity at 37° C. (centistokes)                               .sup.d Particle Size Distribution mean by laser light scatterer               (nanometers)                                                             

    ______________________________________                                        Emulsion DBF2-78 (PFCO).sup.a  A!                                             ______________________________________                                                   Post Sterilization                                                 Ingredient   w/w %       w/v %   v/v %                                        ______________________________________                                        lecithin     1.36        1.79    1.79                                         safflower oil                                                                              1.54        2.02    2.20                                         glycerin     1.23        1.62    1.28                                         PFCO         53.87       70.79   39.55                                        ______________________________________                                                     pH     Osm       Visc PSD                                        ______________________________________                                        pre-sterilization                                                                          8.86   308       7.78 251                                        post-sterilization                                                                         8.25   314       6.85 309                                        ______________________________________                                         .sup.a Perfluorochlorononane.                                            

    ______________________________________                                        Emulsion RAS6-54 (PFDCO).sup.a  B!                                            ______________________________________                                                   Post Sterilization                                                 Ingredient   w/w %       w/v %   v/v %                                        ______________________________________                                        lecithin     1.53        2.02    2.02                                         safflower oil                                                                              1.51        1.99    2.16                                         glycerin     1.30        1.71    1.35                                         PFDCO        53.82       70.72   39.51                                        ______________________________________                                                     pH     Osm       Visc PSD                                        ______________________________________                                        pre-sterilization                                                                          8.85   3.34      9.22 187                                        post-sterilization                                                                         8.58   3.27      7.98 199                                        ______________________________________                                         .sup.a Perfluorodichlorooctane(1,8-perfluorodichlorooctane)              

    ______________________________________                                        Emulsion RAS6-56 (PFDCO)  B!                                                  ______________________________________                                                   Post Sterilization                                                 Ingredient   w/w %       w/v %   v/v %                                        ______________________________________                                        lecithin     1.53        2.01    2.01                                         safflower oil                                                                              1.47        1.93    2.10                                         glycerin     1.23        1.62    1.28                                         PFDCO*       53.98       70.97   39.65                                        ______________________________________                                                     pH     Osm       Visc PSD                                        ______________________________________                                        pre-sterilization                                                                          8.80   2.83      6.05 184                                        post-sterilization                                                                         8.35   2.78      5.93 196                                        ______________________________________                                         *included isomers                                                        

    ______________________________________                                        Emulsion RAS9-12 (PFDCO)  B!                                                  ______________________________________                                                   Post Sterilization                                                 Ingredient   w/w %       w/v %   v/v %                                        ______________________________________                                        lecithin     3.04        3.98    4.33                                         safflower oil                                                                              0.00        0.00    0.00                                         glycerin     1.23        1.61    1.28                                         PFDCO        53.64       70.26   39.25                                        ______________________________________                                                     pH     Osm       Visc PSD                                        ______________________________________                                        pre-sterilization                                                                          8.69   330       7.33 174                                        post-sterilization                                                                         8.20   336       7.46 213                                        ______________________________________                                    

    ______________________________________                                        Emulsion RAS9-14 (PFDCO)  B!                                                  ______________________________________                                                   Post Sterilization                                                 Ingredient   w/w %       w/v %   v/v %                                        ______________________________________                                        lecithin     0.38        .50     .55                                          safflower oil                                                                              0.00        0.00    0.00                                         glycerin     1.25        1.65    1.31                                         PLURONIC     2.67        3.51    3.51                                         PFDCO        53.86       70.87   39.59                                        ______________________________________                                                     pH     Osm       Visc PSD                                        ______________________________________                                        pre-sterilization                                                                          8.30   307       21.70                                                                              187                                        post-sterilization                                                                         7.76   325        8.95                                                                              311                                        ______________________________________                                    

    ______________________________________                                        Emulsion RAS9-18 (1,2 PFDCO)  B!                                              ______________________________________                                                   Post Sterilization                                                 Ingredient   w/w %       w/v %   v/v %                                        ______________________________________                                        lecithin     1.51        1.97    1.97                                         safflower oil                                                                              1.50        1.97    2.14                                         glycerin     1.26        1.65    1.31                                         1,2 PFDCO*   53.36       69.91   39.06                                        ______________________________________                                                     pH     Osm       Visc PSD                                        ______________________________________                                        pre-sterilization                                                                          7.96   336       6.96 172                                        post-sterilization                                                                         6.99   337       5.63 192                                        ______________________________________                                         *1,2 Perfluorodichlorooctane, included isomers                           

    ______________________________________                                        Emulsion RAS10-28 (PFDCO)  B!                                                 ______________________________________                                                   Post Sterilization                                                 Ingredient   w/w %       w/v %   v/v %                                        ______________________________________                                        lecithin     0.38        0.50    0.50                                         Pluronic F-68                                                                              2.67        3.50    3.50                                         safflower oil                                                                              0.00        0.00    0.00                                         glycerin     1.24        1.64    1.30                                         PFDCO        54.19       71.32   39.84                                        ______________________________________                                                     pH     Osm       Visc PSD                                        ______________________________________                                        pre-sterilization                                                                          8.59   314       17.70                                                                              201                                        post-sterilization                                                                         8.23   322        9.35                                                                              345                                        ______________________________________                                    

    ______________________________________                                        Emulsion RAS10-30 (PFDCO)  B!                                                 ______________________________________                                                   Post Sterilization                                                 Ingredient   w/w %       w/v %   v/v %                                        ______________________________________                                        lecithin     2.56        3.50    3.50                                         safflower oil                                                                              0.00        0.00    0.00                                         glycerin     1.29        1.69    1.34                                         PFDCO        53.59       70.36   39.31                                        ______________________________________                                                     pH     Osm       Visc PSD                                        ______________________________________                                        pre-sterilization                                                                          8.95   327       6.81 202                                        post-sterilization                                                                         8.42   333       8.45 227                                        ______________________________________                                    

    ______________________________________                                        Emulsion RAS10-18 (PFDCO)  C!                                                 ______________________________________                                                   Post Sterilization                                                 Ingredient   w/w %       w/v %   v/v %                                        ______________________________________                                        lecithin     1.61        2.09    2.09                                         safflower oil                                                                              1.53        1.99    2.16                                         PFDCO        54.10       70.31   40.18                                        ______________________________________                                                     pH     Osm       Visc PSD                                        ______________________________________                                        pre-sterilization                                                                          8.65   *         *    260                                        post-sterilization                                                                         7.86   *         *    257                                        ______________________________________                                         *not calculated in a nonglycerin-containing emulsion                     

EXAMPLE 11 Perfluorochloroethers

The quantity of lecithin, safflower oil and perfluorochloroether (PFCE)in each emulsion (A-G) is equivalent to 2.00±0.05 w/v% lecithin,2.00±0.05 w/v% safflower oil, and 40±2 v/v% PFCE. Theperfluorochloroethers in emulsions A-G were synthesized fromfluorochlorether precursors using liquid phase direct fluorination. ThepH of the composition was adjusted to 7.5 to 9.0 with 5% aqueous sodiumcarbonate monohydrate prior to sterilization at 121° C. for 15 minutes.The emulsions are both reproducible and stable to heat sterilization.

    __________________________________________________________________________    Perfluorochloroether Emulsions  B!                                                     Lecithin                                                                          Oil Glycerin                                                                           Na.sub.2 CO.sub.3.H.sub.2 O                                                          H.sub.2 O                                                                          PFCE                                          Emulsion                                                                             (g) (g) (g)  (g)    (g)  (g)                                         __________________________________________________________________________    A (RAS7-62).sup.a                                                                      5.02                                                                              4.94                                                                              4.08 0.048  137.1                                                                              172.64                                      B (RAS9-4).sup.a                                                                       22.00                                                                             21.7                                                                              18.07                                                                              0.20   601.9                                                                              776.80                                      C (RAS9-6).sup.a                                                                       7.01                                                                              6.97                                                                              5.85 0.097  191.1                                                                              242.55                                      D (RAS9-30).sup.a                                                                      7.00                                                                              6.94                                                                              5.83 0.074  192.0                                                                              242.07                                      E (RAS9-44).sup.a                                                                      16.98                                                                             16.81                                                                             14.26                                                                              0.19   463.4                                                                              589.94                                      F (RWF12-96).sup.b                                                                     5.05                                                                              4.95                                                                              4.22 0.028  136.6                                                                              166.17                                      G (RWF12-98).sup.c                                                                     5.46                                                                              5.36                                                                              4.47 0.033  147.80                                                                             186.03                                      __________________________________________________________________________               pH     Osm   Visc   PSD                                            __________________________________________________________________________    Emulsion A                                                                    pre-sterilization                                                                        8.69   313   8.65   220                                            post-sterilization                                                                       8.09   316   7.98   236                                            Emulsion B                                                                    pre-sterilization                                                                        8.45   348   10.6   213                                            post-sterilization                                                                       7.65   346   9.87   215                                            Emulsion C                                                                    pre-sterilization                                                                        8.85   339   9.02   201                                            post-sterilization                                                                       8.33   334   8.13   216                                            Emulsion D                                                                    pre-sterilization                                                                        8.82   329   8.90   216                                            post-sterilization                                                                       8.36   330   8.45   232                                            Emulsion E                                                                    pre-sterilization                                                                        8.71   342   11.3   245                                            post-sterilization                                                                       8.03   343   10.9   266                                            Emulsion F                                                                    pre-sterilization                                                                        8.10   324   5.81   264                                            post-sterilization                                                                       7.59   319   5.90   264                                            Emulsion G                                                                    pre-sterilization                                                                        8.28   327   7.50   266                                            post-sterilization                                                                       7.77   320   7.31   273                                            __________________________________________________________________________     .sup.a perfluoro-bis-chlorobutyl ether (PFBCBE) Cl--C.sub.4 F.sub.8           --O--C.sub.4 F.sub.8 --Cl.                                                    .sup.b C.sub.4 F.sub.9 --O--C.sub.2 F.sub.4 --O--C.sub.2 F.sub.4 --Cl.        .sup.c C.sub.6 F.sub.13 --O--C.sub.2 F.sub.4 --O--C.sub.2 F.sub.4 --Cl.  

To model stability in the human circulation, emulsions A, B and E wereadmixed 1:1 with a 5% solution of human serum albumin in lactatedRinger's solution. After incubation in this medium for 4 days at 37° C.,the mean particle size distribution was 289 nanometers for example A,265 nanometers for example B and 263 nanometers for example E. Theemulsions are clearly stable under these conditions as well.

EXAMPLE 12

Emulsion C (Example 11) was infused intravenously into two groups of200-250 g albino Sprague Dawley male rats at a rate of 1 cc/min to atotal dose of 10 cc/kg (40 animals) or 20 cc/kg (20 animals). Onequarter of each group was sacrificed at 2, 16, 30, and 60 dayspost-infusion. The clearance of perfluoro-bis-chlorobutyl ether (PFBCBE)was measured by analyzing the liver, lung, spleen, and bone marrow fromeach animal. The tissue was ground in a Tissuemizer, extracted with anorganic solvent, e.g., chloroform, carbontetrachloride ortrifluoro-trichloro ethane, and analyzed by gas chromatography.

FIG. 1 depicts the average percent dose of PFBCBE remaining in each ofthe four organs at each timepoint post-infusion. Nearly all of theperfluorocarbon cleared the major tissues by 60 days in rats receiving atotal of 10 cc/kg PFBCBE, and is obviously in the process of eliminationin rats receiving a dose of 20 cc/kg PFBCBE. Thus, PFBCBE emulsionsclear the body at an acceptable rate.

While we have hereinbefore described various embodiments of ourinvention, it should be apparent that other embodiments also existwithin the scope of the invention. Therefore, it should be understoodthat the scope of this invention is to be defined by the claims ratherthan the specific embodiments which have been presented hereinbefore byway of example.

We claim:
 1. An emulsion comprising perfluoro-bis-chlorobutylether. 2.The emulsion according to claim 1 wherein theperfluoro-bis-chlorobutylether is present in an amount up to about 60%by volume.
 3. The emulsion according to claim 1 wherein theperfluoro-bis-chlorobutylether is present in an amount from about 10% toabout 50% by volume.
 4. The emulsion according to claim 3 wherein theperfluoro-bis-chlorobutylether is present in an amount from about 25% toabout 40% by volume.
 5. The emulsion according to claim 1 furthercomprising a surfactant.
 6. The emulsion according to claim 5 whereinthe surfactant is a physiologically acceptable surfactant.
 7. Theemulsion according to claim 6 wherein the surfactant is lecithin.
 8. Theemulsion according to claim 7 further comprising an oil that is notsubstantially surface active and not significantly water soluble.
 9. Theemulsion according to claim 8 wherein the oil is a physiologicallyacceptable oil.
 10. The emulsion according to claim 9 wherein the oil isselected from the group consisting of safflower oil and soybean oil. 11.The emulsion according to claim 1 further comprising at least onecompound selected from the group consisting of isotonic agents, osmoticpressure controlling agents, serum extending agents and antioxidants.12. An artificial blood comprising an amount of an emulsion according toany one of claims 1 to 4, or 5 to 11, said amount being therapeuticallyeffective for oxygen transport and delivery in humans.
 13. A compositionfor minimizing the adverse effects of coronary angioplasty comprising atherapeutically effective amount of an emulsion according to any one ofclaims 1 to 4 or 5 to
 11. 14. A contrast agent for biological imagingcomprising an amount of an emulsion according to any one of claims 1 to4 or 5 to 11, said amount being clinically effective for imaging byx-ray, ultrasound, computed tomography, nuclear magnetic resonance, ¹⁹F-magnetic resonance imaging or positron emission tomography.
 15. Acomposition for enhancing cancer radiation treatment and chemotherapycomprising a therapeutically effective amount of an emulsion of any oneof claims 1 to 4 or 5 to
 11. 16. A composition for preserving organscomprising a preserving effective amount of an emulsion according to anyone of claims 1 to 4 or 5 to
 11. 17. A composition for treating heartattack, stroke and vascular occlusions comprising a therapeuticallyeffective amount of an emulsion according to any one of claims 1 to 4 or5 to
 11. 18. A method for sustaining the oxygen requirements of livingorganisms or their cellular constituents comprising the step ofadministering to a patient in a therapeutically acceptable manner anemulsion according to claim
 12. 19. A method for minimizing the adverseeffects of coronary balloon angioplasty by perfusion of an emulsionaccording to claim 13 through the central lumen of the catheter.
 20. Amethod for biological imaging of internal organs and bloodflow using thecontrast agent of claim 14 in conjunction with x-ray, computedtomography, ultrasound, magnetic resonance imaging, ¹⁹ F-magneticresonance imaging, or positron emission tomography.
 21. A method forenhancing cancer radiation and chemotherapy comprising the step ofadministering to a patient in a therapeutically acceptable manner anemulsion according to claim
 15. 22. A method for preserving organs byperfusion of an emulsion according to claim
 16. 23. A method fortreating heart attack, stroke and vascular occlusions comprising thestep of administering to a patient in a therapeutically acceptablemanner an emulsion according to claim 17.